This video goes over the process to get AT&T to officially and permanently unlock your iPhone locked to AT&T.
1. Get IMEI # ready.
◦Tap Settings app then tap General;
◦Tap “About” and scroll down to find “IMEI”
2. Call AT&T: 1-800-331-0500 and then don’t talk and wait until you get a rep (International users dial 1-800-335-4685)
3. Request your iPhone to be unlocked, provide the IMEI number of the device, and then wait for the instructions to be emailed to you
1. None! Ask in the comments.
Video credits to the YouTube channel owner